BDKRB1 and metastatic malignant neoplasm in the lymph nodes: Subsequently, the Chi-square test was used to analyze the relationship between hub genes BDKRB1, NMUR2, PMCH, and SAA1 expression level and pathological characteristics of pRCC patients, and the results showed that the expression level of hub genes BDKRB1, NMUR2, PMCH, and SAA1 expression in pRCC tissues were significantly positively correlated with tumor stage, lymph node metastasis, and histopathological grade of pRCC patients (Figures 4(b), 4(d), 4(f), and 4(h)), while the relationship with gender and age of patients was not statistically significant (Tables 3, , –6).